engleski

Synthesis and photochemistry of novel n-phthalimido dipeptides

Photochemistry of phthalimides is a useful synthetic tool giving rise to different polycyclic compounds arising from intramolecular H-abstraction, cycloaditions or photoinduced electron transfer (PET) reactions.[1] For example, it was demonstrated that photodecarboxlyative cyclization of N-phenylphthalimide carboxylic acids leads to the formation of medium-size rings.[2] On the other hand, we have shown that PET induced decarboxylative addition of 3-(N-phthalimido)adamantanecarboxylic acid on electron deficient alkenes can be used for the synthesis of more complex phthalimidoadamantane systems.[3] In continuation of our investigation we have prepared a series of dipeptides 1a, b with a glycine or L-phenylalanine at the C-terminus. In adition, to determine the influence of the rigid spacer between the phthalimide (electron acceptor) and the carboxylic group (electron donor), we have prepared the phenyl analogues of dipeptides 2a, b. On irradiation of the dipeptides, photodecarboxlation takes place, and in the case of adamantyl derivatives, gives cyclization products 4. The mechanism of the photochemical reaction was elucidated by preparative irradiations and laser flash photolysis.

photochemistry of phthalimides ; N-phthalimido dipeptides

nije evidentirano